Immobilization of Lipases by Adsorption on Hydrophobic Supports: Modulation of Enzyme Properties in Biotransformations in Anhydrous Media.

Adsorption of lipases on hydrophobic supports is a very easy immobilization protocol and it yields very interesting immobilized lipase derivatives. The open and active form of lipase molecules becomes stabilized by strong adsorption on the support surface. By using very rigid hydrophobic supports (e.g., methacrylate), lipase derivatives are very useful to catalyze biotransformations in fully anhydrous organic media (solvents, solvent-free systems, etc.) and design of continuous flow reactors. In addition to that, the design of different lipase derivatives allows the modulation of functional properties of the derivatives. In this chapter, methodology of immobilization into hydrophobic carriers is described using as case study the preparation of immobilized biocatalysts of Thermomyces lanuginosus lipase (TLL), and the following particular features will be discussed: 1. Adsorption on hydrophobic supports yields lipase derivatives that are much more active and stable than other immobilized lipase derivatives. 2. Regioselectivity can be modulated, for example, TLL adsorbed on divinyl benzene hydrophobic supports retains a 1,3 regioselectivity during ethanolysis of oils. On the contrary, the enzyme adsorbed on octadecyl supports loses the regioselectivity and allows the complete ethanolysis of oils (e.g., biodiesel synthesis). 3. TLL adsorbed on octadecyl supports with large pore size (60 nm) is tenfold more active for ethanolysis in solvent-free systems than TLL derivatives adsorbed on supports with small pore size (10 nm).